21221110111021 has 8 divisors (see below), whose sum is σ = 22338876336800. Its totient is φ = 20103430454640.

The previous prime is 21221110110989. The next prime is 21221110111037. The reversal of 21221110111021 is 12011101112212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221110111021 - 2⁵ = 21221110110989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221110110986 and 21221110111004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221110111921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21138870 + ... + 22119991.

It is an arithmetic number, because the mean of its divisors is an integer number (2792359542100).

Almost surely, 2^{21221110111021} is an apocalyptic number.

It is an amenable number.

21221110111021 is a deficient number, since it is larger than the sum of its proper divisors (1117766225779).

21221110111021 is a wasteful number, since it uses less digits than its factorization.

21221110111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43284699.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21221110111021 its reverse (12011101112212), we get a palindrome (33232211223233).

The spelling of 21221110111021 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred ten million, one hundred eleven thousand, twenty-one".